Washington(Agencies): US Secretary of State Hillary Clinton on Saturday asked her Chinese counterpart to convey US concern to Beijing's ally North Korea after its defiant but unsuccessful rocket launch.

Clinton,who was heading on Saturday to a summit in Colombia, spoke on telephone with Chinese Foreign Minister Yang Jiechi as she sought a "unified way to speak out and condemn this action," State Department spokesman Mark Toner said.

"We're asking them to use their relationship with North Korea to convey our concern about their recent actions," Toner told reporters.

China is believed to have the most influence over North Korea and the United States has repeatedly urged the rising Asian power to rein in its isolated and heavily militarisedneighbour.

China had taken the rare step of criticising the launch plan, which came just weeks after the United States and North Korea sealed an agreement negotiated in Beijing for a freezeon Pyongyang's nuclear and missile programmes.

After Pyongyang went ahead, China urged "calm and restraint" from all sides. North Korea said it failed to put a satellite into orbit, in a launch that the United States and South Korea considered a disguised missile test.